A variety of different devices have been used to retract delicate tissue during surgical procedures. One such device is illustrated in United States Patent Publication Number 2010/0010315 (“Mangiardi”), to which this application claims priority and which is incorporated herein by reference in its entirety. Mangiardi shows two general versions of a retractor for delicate tissue. One version is a closed-channel retractor in the form of a tube (see, e.g., Mangiardi FIG. 3), and the other is an open-channel retractor in the form of a curved channel (see, e.g., Mangiardi FIG. 23).
FIG. 1 of this application illustrates a soft tissue retractor system such as found in Mangiardi. The retractor system includes a hollow retractor 100, and an introducer 102 that is selectively inserted into the retractor 100. The retractor 100 and/or introducer 102 may include a handle 104 to facilitate manipulation and placement of the retractor system, and a lock to hold the introducer and retractor together. The illustrated handle 104 is molded integrally with the retractor 100, but it may be a separate part. The handle 104 may be configured to connect to a clamp 106, such as the standard surgical clamp 106 shown in FIG. 1. In this example, the handle 104 has a ridge 108 that fits into a corresponding groove 110 on the clamp 106, to prevent relative rotation between the two when engaged. Modifications to this design are described in Mangiardi.
A retractor system such as shown in FIG. 1 is often used by inserting the introducer 102 into the retractor 100 and locking it in place, so the two can be moved and manipulated as a unit. The combined introducer/retractor system is inserted into the patient's body and moved to the surgery site, and then the introducer 102 is unlocked and removed to permit access to the site through the retractor 100. When the unit is in place (either before or after the introducer 102 is removed), the handle 104 may be locked to a clamp 106 to hold the retractor 100 in place. An example of this procedure is shown in FIGS. 16-20 of Mangiardi. Surgeons using the Mangiardi retractor sometimes do not use a clamp to hold the retractor at the surgery site, and often manually manipulate the retractor to access different parts of the surgery site during the surgical procedure. The introducer/retractor system and the retractor may be manipulated by holding the proximal ends of the introducer or retractor or by holding the handle.
The device shown in Mangiardi may have a transparent introducer 102 and/or retractor 100, and surgeons using such devices advantageously use the transparent introducer and retractor to manually guide the unit to the surgery site. While it has been found that visual guidance by looking through the introducer 102 is very beneficial, it also has been found that some form of additional guidance or navigation may be desired in some cases. For example, in some cases, surgeons have used a stylet (a narrow elongated rod) to guide the movement of the introducer/retractor system. In such cases, the stylet is advanced to the surgery site, and then the interlocked introducer/retractor system is slid over the stylet until it reaches the surgery site. This is facilitated by the inclusion of a hole at the tip of the introducer that fits around the stylet. If the hole through the tip of the introducer is absent, this method cannot be used.
It has been found that some surgeons using the above procedure may use a stylet that is integrated into a computer navigation system. For example, the stylet may include a so-called “starburst” or the like, on the stylet's proximal end (i.e., the end opposite the distal end that is inserted to the surgical site). This and other navigation systems are known in the art. For example, frameless navigation systems and other computerized guidance systems and methods are described in U.S. Publication No. 2001/0027271, and others, and are commercially available from companies such as Medtronic, Inc., Stryker, BrainLab, AG, Ge Healthcare. The foregoing reference is incorporated herein by reference in its entirety. As used herein, “computerized guidance” encompasses any method of guiding a device to or at a surgical site that relies on computer visualization and/or control, as opposed to direct visual inspection and/or manual movement. Mangiardi briefly notes the possibility of using stereotactic guidance or navigation in conjunction with a surgical retractor, but does not illustrate or describe this procedure or any apparatus for accomplishing this objective.
While computerized surgical guidance systems are well-known, a number of limitations exist with respect to their use with introducer/retractor systems, and particularly with systems like those shown in Mangiardi. For example, while some surgeons use computerized guidance to direct a stylet to the surgery site, and then slide the introducer/retractor system over the stylet to the site, the movement of the introducer/retractor may be somewhat imprecise and the process can be unduly cumbersome. This method also is not available if the introducer/retractor system does not have a through-hole that fits over the stylet (due either to the absence of a hole or a hole that is too small). In addition, the stylet does not provide a view of the tissue through which it is advanced, so there is no visual means to perceive and avoid critical tissue (e.g., major blood vessels or nerves) when inserting a stylet before inserting a retractor/introducer system. Also, the small-diameter stylet may sever delicate tissue cells, such as grey or white brain matter, rather than moving the cells aside and passing between them as would be expected to happen when advancing the introducer/retractor system.
While preexisting navigation system devices have been used with delicate tissue introducers and retractors, there still exists a need to provide alternative solutions. In addition, there is a need to provide alternatives to existing systems for manipulating, introducing and holding retractors.